1. Field of the Invention
The present invention relates to the preparation of p-fuchsones and also to the synthesis of p-dihydroxylated aromatic compounds from p-fuchsone reagents, in particular from the p-fuchsones thus prepared.
2. Description of the Prior Art
There are scant references in the literature describing the synthesis of fuchsones. Typically, their preparation is based on the dehydration of a carbinol.
Thus, I. S. Ioffe et al, J. Gen. Chem. USSR, 19, pages 917-28 (1949), describes the preparation of 4-hydroxy triphenyl carbinol by reacting Ph.sub.2 CCl.sub.2 with molten phenol.
H. Burton et al, J. Chem. Soc., 3089-3090 (1955), describes the synthesis of 4-hydroxy triphenyl carbinol via the addition of Ph.sub.2 CCl.sub.2 to a suspension of aluminum chloride in carbon disulfide and then introducing into that reaction medium phenol in solution in carbon disulfide.
The 4-hydroxy triphenyl carbinol thus obtained is then dehydrated. One dehydration technique described by I. S. Ioffe et al, supra, comprises heat-treating the carbinol after the addition of acetic acid thereto, thus providing the following fuchsone: ##STR1##
Notable disadvantages presented by the processes heretofore known to this art include the reality that it is virtually impossible to carry out same on an industrial scale by virtue of a raw material which is difficult to obtain (Ph.sub.2 CCl.sub.2) and the difficulty in handling reactants such as aluminum chloride and carbon disulfide.